The inverse of Nice Character, Mean Actor -- the guy playing the Big Bad, the Badass, or the For the Evulz Evil Overlord is, off-camera, the nicest, sweetest person you'll ever meet. Maybe they were previously pigeonholed into nice guys roles and they're relishing the chance for Playing Against Type; maybe they're in it for the Money, Dear Boy; maybe they're the resident Large Ham and they just like playing deliciously evil characters; or they could have been cast based on looks: just because a person looks big and scary doesn't mean they really are. See also Scary Musician, Harmless Music.